Single- and Multi-Sensor Acoustic Association for Sonobuoys

The Aircraft Carrier Tactical Support Center (CV-TSC) performs acoustic detection and feature extraction on passive sonobuoy sensors. Algorithms are needed to associate multiple frequency components originating from a contact, exploit signature content to improve associations across sensors and over time, and enable fusion of the characterized sonar tracks across the sonobuoy field or with radar or other non-acoustic sources. Recently, the submarine Advanced Processor Build (APB) program developed Single Sensor Association (SSA) functionality that combines all detection sources on a sensor into a single bearing-plus-frequency attribute report. Composite detections were then provided to a Multi-Sensor Association (MSA) algorithm to identify associations across sensors. SSA and MSA were independently tested and transitioned into the APB-11 baseline. Venator Solutions proposes to extend the SSA and MSA functionality to CV-TSC sonobuoys, adapting to the unique characteristics of the sonobuoy sensor. We propose extensions to the acoustic characterization to enable (a) improved SSA associations, (b) joint exploitation of acoustic association and kinematic likelihoods to improve field level fusion, and (c) evidential reasoning on acoustic and kinematic states to infer contact mode, gross behavior, and eventually contact classification. We cast the fusion process as a Probabilistic Graphical Model to motivate PGM-based evidential reasoning.